The All Terrain Rapid Deployment Pod (AT-RDP) was a type of Imperial assault ship used in planetary invasions.
The pod's observation deck
These massive landing pods could house four AT-STs and several passengers, such as stormtroopers and Reborns. A large number of these pods could be docked underneath the Doomgiver, where they could be launched to land on the planetary surface. They where egg-shaped and held four levels aboard, with an elevator in the center of each level to access the others. Four AT-STs were on the large bottom deck facing each ramps, while passengers were positioned on two higher levels. A commander monitored the ships communication and sensor arrays on the top observation deck.
AT-RDPs were assembled inside the Cairn Installation by the Empire Reborn. At one point, Kyle Katarn had to sabotage the construction of one such ship inside the installation to make his way to the Doomgiver. The pods were later used in the Battle of the Jedi Praxeum to land Remnant troops and walkers, including Stormtroopers, Swamptroopers, Reborns, Shadowtroopers and AT-STs. While some pods managed to land on the Moon, many of them had been destroyed by Rogue Squadron's X-Wings in orbit after Kyle Katarn alterted the squadron using the Doomgiver's communication system.
Similar but smaller pods appear in Star Wars: The Force Unleashed, where they are used to deploy AT-ST walkers on Felucia and Raxus Prime.